I've got this issue with an IBM X3250 M2 that I'm just using at home, using the standard driver fixes the problem.
Although I note from the product guide, it says that the card supports up to 1024x768 only. This is likely the reason we're having issues, I have an older 19" wide Lenovo monitor and it was lagged at 1280x1024 and 1440x900.
Heres what the article said:"Dual video ports — A Matrox G200eV SVGA video controller provides up to 1024x768
resolution, with a color depth of 32 bits at 85Hz refresh rate. To simplify local systemsmanagement, one video port is provided on the front of the unit and one on the back. "
Customer support service by UserEcho